1. Field of the Invention
This invention relates to a middle ear prosthesis.
2. Description of Prior Art
The purpose of tympanoplasty is to reconstruct the eardrum and ossicles (stapes, incus and malleus) of the middle ear which have been destroyed by otitis.
Hitherto this type of surgery has been carried out by the following methods:
1) to reconstruct the eardrum a piece of the temporalis or other tissue of the same patient or alternatively animal tissue deproteinized to prevent rejection are used; to reconstruct the ossicle chain, ceramic or plastic prostheses or remodelled tissue of the patient are used;
2) in the case of homotransplant, an eardrum-ossicle block taken from a cadaver is repositioned in the ear to be reconstructed.
These various reconstructions have the serious drawback of being subject to displacement, reabsorption or rejection, resulting in operational failure. In this respect the surgeon must himself during the surgery construct the parts required for the reconstruction, or in the most favourable case combine partial prostheses (such as ceramic or plastic ossicles) with parts constructed on the spot. Because of this situation the result of the surgery is often dependent on the manual dexterity of the surgeon, which is very variable.
From the foregoing it is apparent that no satisfactory method has as yet been found by which the aforesaid problems which occur with the passage of time are avoided. In the present state of the art about 50% of tympanoplasty operations fail within five years.